/*------------------------------------------------------------------------
 *  ImageScanner
 *
 *  Copyright 2007-2010 (c) Jeff Brown <spadix@users.sourceforge.net>
 *
 *  This file is part of the ZBar Bar Code Reader.
 *
 *  The ZBar Bar Code Reader is free software; you can redistribute it
 *  and/or modify it under the terms of the GNU Lesser Public License as
 *  published by the Free Software Foundation; either version 2.1 of
 *  the License, or (at your option) any later version.
 *
 *  The ZBar Bar Code Reader is distributed in the hope that it will be
 *  useful, but WITHOUT ANY WARRANTY; without even the implied warranty
 *  of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Lesser Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser Public License
 *  along with the ZBar Bar Code Reader; if not, write to the Free
 *  Software Foundation, Inc., 51 Franklin St, Fifth Floor,
 *  Boston, MA  02110-1301  USA
 *
 *  http://sourceforge.net/projects/zbar
 *------------------------------------------------------------------------*/

package net.sourceforge.zbar;

/**
 * Read barcodes from 2-D images.
 */
public class ImageScanner {
	/** C pointer to a zbar_image_scanner_t. */
	private long peer;

	static {
		System.loadLibrary(Config.LIB_ZBAR_DECODER_NAME);
		init();
	}

	private static native void init();

	public ImageScanner() {
		peer = create();
	}

	/** Create an associated peer instance. */
	private native long create();

	protected void finalize() {
		destroy();
	}

	/** Clean up native data associated with an instance. */
	public synchronized void destroy() {
		if (peer != 0) {
			destroy(peer);
			peer = 0;
		}
	}

	/** Destroy the associated peer instance. */
	private native void destroy(long peer);

	/**
	 * Set config for indicated symbology (0 for all) to specified value.
	 */
	public native void setConfig(int symbology, int config, int value)
			throws IllegalArgumentException;

	/** Parse configuration string and apply to image scanner. */
	public native void parseConfig(String config);

	/**
	 * Enable or disable the inter-image result cache (default disabled). Mostly
	 * useful for scanning video frames, the cache filters duplicate results
	 * from consecutive images, while adding some consistency checking and
	 * hysteresis to the results. Invoking this method also clears the cache.
	 */
	public native void enableCache(boolean enable);

	/**
	 * Retrieve decode results for last scanned image.
	 * 
	 * @returns the SymbolSet result container
	 */
	public SymbolSet getResults() {
		return (new SymbolSet(getResults(peer)));
	}

	private native long getResults(long peer);

	/**
	 * Scan for symbols in provided Image. The image format must currently be
	 * "Y800" or "GRAY".
	 * 
	 * @returns the number of symbols successfully decoded from the image.
	 */
	public native int scanImage(Image image);
}
